1. Field of the Invention
This invention relates to wavelength converters of the type desirable in certain wavelength division multiplexed optical communication networks, as well as other applications where it is desirable to change the wavelength of the optical carrier of a modulated lightwave, and more particularly to optoelectronic wavelength converters in which an incoming lightwave having a first wavelength is detected by a photodetector that produces an electrical signal that in turn modulates a source of an outgoing lightwave having a desired second wavelength.
2. Description of the Related Art
Optoelectronic wavelength conversion processes have used as separate photodetectors, receiver and regeneration circuits, transmitter and driver circuits and directly or externally modulated lasers. S. J. B. Yoo, xe2x80x9cWavelength conversion technologies for WDM network applications,xe2x80x9d J. Lightwave Techn. 14 (6) (June, 1996). These discrete-component wavelength converters have tended to be relatively bulky and expensive to manufacture. Also, the lasers generally have a fixed wavelength or a very limited tuning range.
There is a need for a monolithic wavelength converter assembly that provides for the process of detection and regeneration at some other wavelength. There is a need for a monolithic wavelength converter assembly fabricated on one semiconductor substrate using compatible photonic integrated circuit technology for all components. There is a further need for a wavelength converter assembly where signal amplification is obtained without the use of electronic transistors. There is yet a further need for a wavelength converter assembly where conditioning of the signal is done in combination with the detection or modulation process in the optical or electrical domain. There is still a further need for a wavelength converter assembly that has a wide tuning range and all of the components are fabricated on one semiconductor substrate using compatible photonic integrated circuit technology.